If you know how to read it then yes he's correct....
Symbolism is used often in gang graffiti, the interpretation of this tattoo is spot on. M arijuana, S miley face, cross (two meanings in this context) stylized number 1, also stands for the Trinity, so the character in itself is the stylized 1 and 3. Skull which is also often used in MS13 as a stylized number 3 in graffiti. The skull symbolism is often paired with horns that make up an often used street soldier gang sign.
Based on this tattoo he is either an associate business partner or mid level leader. Most likely the former based on this being his only tattoo (at least that I'm aware of)
The other possibility is that he's a poser who used those symbols to fake it, which I place at near zero probability. He wouldn't have made it two weeks on the streets with that tattoo.